scholarly journals Hygroscopic swelling and shrinkage of latewood cell wall micropillars reveal ultrastructural anisotropy

2014 ◽  
Vol 11 (95) ◽  
pp. 20140126 ◽  
Author(s):  
Ahmad Rafsanjani ◽  
Michael Stiefel ◽  
Konstantins Jefimovs ◽  
Rajmund Mokso ◽  
Dominique Derome ◽  
...  
Keyword(s):  
Cell Wall ◽  
Growth Ring ◽  
Ion Beam ◽  
Microfibril Angle ◽  
Cellulose Microfibrils ◽  
Wall Material ◽  
Neighbouring Cell ◽  
Direction Parallel ◽  
Hygroscopic Swelling ◽  
S2 Layer

We document the hygroscopic swelling and shrinkage of the central and the thickest secondary cell wall layer of wood (named S2) in response to changes in environmental humidity using synchrotron radiation-based phase contrast X-ray tomographic nanoscopy. The S2 layer is a natural fibre-reinforced nano-composite polymer and is strongly reactive to water. Using focused ion beam, micropillars with a cross section of few micrometres are fabricated from the S2 layer of the latewood cell walls of Norway spruce softwood. The thin neighbouring cell wall layers are removed to prevent hindering or restraining of moisture-induced deformation during swelling or shrinkage. The proposed experiment intended to get further insights into the microscopic origin of the anisotropic hygro-expansion of wood. It is found that the swelling/shrinkage strains are highly anisotropic in the transverse plane of the cell wall, larger in the normal than in the direction parallel to the cell wall's thickness. This ultrastructural anisotropy may be due to the concentric lamellation of the cellulose microfibrils as the role of the cellulose microfibril angle in the transverse swelling anisotropy is negligible. The volumetric swelling of the cell wall material is found to be substantially larger than the one of wood tissues within the growth ring and wood samples made of several growth rings. The hierarchical configuration in wood optimally increases its dimensional stability in response to a humid environment with higher scales of complexity.

Microtubules and cell wall development in differentiating protophloem sieve elements of Triticum aestivum L

1987 ◽  
Vol 87 (4) ◽  
pp. 595-607
Author(s):  
E. P. ELEFTHERIOU
Keyword(s):  
Cell Wall ◽  
Triticum Aestivum L ◽  
Cellulose Microfibrils ◽  
Wall Material ◽  
Wall Thickening ◽  
Sieve Elements ◽  
Material Deposition ◽  
Cellulose Microfibril Orientation ◽  
Cell Wall Development ◽  
Developing Area

The densities of microtubules (MTs) along the lateral walls of developing sieve elements in root protophloem of wheat have been investigated by electron microscopy. They increase gradually in the very young sieve elements to reach a maximum just before the initiation of wall thickening. During wall increment MTs remain at high densities (more than 10 MTs μm−1), but their number declines abruptly when wall material deposition ceases. Cell wall thickening is not uniform: broad ridges alternate with narrow depressions, the latter occupied by plasmodesmata. During wall material deposition MTs overlie the thickenings only, being entirely absent from the non-thickened areas. The orientation of MTs reflects that of the currently deposited cellulose microfibrils in the cell wall, all being perpendicular to the direction of cell expansion. Numerous vesicles, apparently of Golgi apparatus origin, are encountered amongst the cortical arrays of MTs. Though the least spacing between the contiguous MTs is much smaller than the diameter of even the smallest vesicles, the latter were seen amongst the MTs, indicating that MTs do not prevent the vesicles from passing between them towards the developing area. All results favour the suggestion that MTs in sieve elements are involved in cell wall pattern development, cellulose microfibril orientation, and presumably in cell elongation.

Studies of the structure and chemical composition of the cell walls of Vaucheriaceae and Saprolegniaceae

1963 ◽  
Vol 158 (973) ◽  
pp. 435-445 ◽  
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Insoluble Fraction ◽  
Water Soluble ◽  
Hot Water ◽  
Cellulose Microfibrils ◽  
Wall Material ◽  
Native Cellulose ◽  
A Cell ◽  
Crystalline Component

The cell walls of members of the Vaucheriaceae and Saprolegniaceae have been examined by X-ray analysis and electron microscopy, and their composition determined by hydrolysis and paper partition chromatography of the hydrolysates. Both differences and similarities between the members of these two species examined are found to supplement the comparative morphological and physiological information at present available. Saprolegnia , Achlya , Brevilegnia and Dictyuchus among the Saprolegniaceae possess hot-water soluble polysaccharides containing glucose residues only. This polysaccharide is not crystallographically identical with the polysaccharide found in Vaucheria sessilis with a similar solubility. The members of the Saprolegniaceae contain large amounts of alkali-soluble polysaccharides in contrast with the negligible amount found in V. sessilis . These polysaccharides are only weakly crystalline, but the indications are that the same polysaccharides may occur through­out the Saprolegniaceae. The alkali-insoluble wall material of Vaucheria species consists of highly crystalline native cellulose with large, apparently randomly arranged, microfibrils. The hydrolysate of this material contains ribose, xylose and arabinose in addition to glucose, presumably representing strongly bound pentosans. Native cellulose also occurs in the Saprolegniaceae but only in small proportion. The bulk of the alkali-insoluble fraction in the walls of these fungi appears amorphous in the electron microscope and is only weakly crystalline. It consists of one or m ore substances containing glucose, mannose, ribose and possibly other sugars together with traces of glucosamine. These substances presumably cover the cellulose microfibrils. The total quantity of non-cellulosic polysaccharide in the Saprolegniaceae approaches 85% of the total wall weight in contrast with the situation in Vaucheria where the cellulose alone approaches 90% of the total cell wall. Dichotomosiphon is unique among the organism s studied in this paper, in possessing a cell wall entirely soluble in alkali and composed of approximately equal quantities of glucose and xylose. The crystalline component is aβ-1,3-linked xylan, as already reported for some of the Siphonales (closely related algae) by Frei & Preston.

The interrelation between microfibril angle (MFA) and hygrothermal recovery (HTR) in compression wood and normal wood of Sugi and Agathis

Holzforschung ◽  
2014 ◽  
Vol 68 (7) ◽  
pp. 823-830 ◽  
Author(s):  
Midori Tanaka ◽  
Hiroyuki Yamamoto ◽  
Miho Kojima ◽  
Masato Yoshida ◽  
Miyuki Matsuo ◽  
...  
Keyword(s):  
Cell Wall ◽  
Tensile Stress ◽  
Compressive Stress ◽  
Matrix Theory ◽  
Microfibril Angle ◽  
Hot Water ◽  
Cellulose Microfibrils ◽  
Elastic Component ◽  
Normal Wood ◽  
Axial Tensile

Abstract Tree growth stress (GS) consists of an elastic component and a viscoelastic locked-in component. The elastic component is released instantaneously by cutting wood, whereas the locked-in component remains. The latter can be released by hot water treatment, which is known as hygrothermal recovery (HTR). In this paper the mechanism behind HTR is described and interpreted in terms of the microfibril angle (MFA) in the cell wall as follows: during cell-wall maturation, axial tensile stress is generated in the cellulose microfibrils (CMF), whereas isotropic compressive stress is generated in the matrix of lignin-hemicellulose (MT). Some amount of microscopic stresses remains following the removal of the wood from the living stem. Hygrothermal (HT) treatment induces recovery of remaining compressive stress in the MT, which causes its expansion. Axial tensile stress in the CMF are released by HT softening of the MT. This causes the CMF to contract along its length and to expand laterally. The combined effect of the expansions of the MT and contraction of the CMF causes the wood to deform anisotropically. This is the HTR of wood. The degree of anisotropy is determined by the MFA on the basis of reinforced-matrix theory.

Application of Small-Angle X-Ray Scattering to Predict Microfibril Angle in Acacia mangium Wood

2010 ◽  
Vol 173 ◽  
pp. 72-77
Author(s):  
Tabet A. Tamer ◽  
Aziz Abdul Haji Fauziah ◽  
Radiman Shahidan
Keyword(s):  
Cell Wall ◽  
Standard Deviation ◽  
Intensity Distribution ◽  
Small Angle ◽  
Cell Walls ◽  
Microfibril Angle ◽  
Acacia Mangium ◽  
Cellulose Microfibrils ◽  
X Ray ◽  
X Ray Scattering

Partially crystalline cellulose microfibrils are wound helically around the longitudinal axis of the wood cell. A method is presented for the measurement, using small-angle X-ray scattering (SAXS), of the microfibril angle, (MFA) and the associated standard deviation for the cellulose microfibrils in the S2 layer of the cell walls of Acacia mangium wood. The length and orientation of the microfibrils of the cell walls in the irradiated volume of the thin samples are measured using SAXS and scanning electron microscope, (SEM). The undetermined parameters in the analysis are the MFA, (M) and the standard deviation (σФ) of the intensity distribution arising from the wandering of the fibril orientation about the mean value. Nine separate pairs of values are determined for nine different values of the angle of the incidence of the X-ray beam relative to the normal to the radial direction in the sample. The results show good agreement. The curve distribution of scattered intensity for the real cell wall structure is compared with that calculated with that assembly of rectangular cells with the same ratio of transverse to radial cell wall length. It is demonstrated that for β = 45°, the peaks in the curve intensity distribution for the real and the rectangular cells coincide. If this peak position is Ф45, Then the MFA can be determined from the relation M = tan-1 (tan Ф45 / cos 45°), which is precise for rectangular cells.

Properties of chemically and mechanically isolated fibres of spruce (Picea abies[L.] Karst.). Part 2: Twisting phenomena

Holzforschung ◽  
2005 ◽  
Vol 59 (2) ◽  
pp. 247-251 ◽  
Author(s):  
Ingo Burgert ◽  
Klaus Frühmann ◽  
Jozef Keckes ◽  
Peter Fratzl ◽  
Stefanie Stanzl-Tschegg
Keyword(s):  
Cell Wall ◽  
Picea Abies ◽  
Microfibril Angle ◽  
Cell Wall Assembly ◽  
Opposite Wood ◽  
Wood Compression ◽  
Mechanical Isolation ◽  
Wall Assembly ◽  
S2 Layer ◽  
Lateral Cell

Abstract The twisting behaviour of chemically and mechanically isolated fibres of spruce (Picea abies[L.] Karst.) was examined. Mechanical isolation was carried out using very fine tweezers to obtain fibres with an unmodified cell wall assembly. Chemical isolation was achieved using hydrogen peroxide and glacial acetic acid, leading to partial degradation of lignin and hemicelluloses. Besides normal adult wood, compression wood and opposite wood fibres were investigated. Fibre twisting while drying increased with higher microfibril angles in the S2 layer, and was significantly less pronounced for mechanically isolated compared to chemically macerated fibres. A simple model is introduced that takes into account the interdependency between lateral cell-wall shrinkage and the microfibril angle in the S2 cell wall.

Wood microfibril angle variation after drying

Holzforschung ◽  
2016 ◽  
Vol 70 (5) ◽  
pp. 485-488 ◽  
Author(s):  
Vinicius Lube ◽  
Ciprian Lazarescu ◽  
Shawn D. Mansfield ◽  
Stavros Avramidis
Keyword(s):  
Cell Wall ◽  
Moisture Content ◽  
Cell Walls ◽  
Wood Cell Wall ◽  
Microfibril Angle ◽  
Cellulose Microfibrils ◽  
Lateral Deformation ◽  
Angle Variation ◽  
Water Desorption

Abstract The change of microfibril angle (MFA) in wood cell wall was assessed after drying at 60°C and 70°C to a target moisture content (MC) of 8% or 15%. Despite literature contradictions about the effect of drying on MFA, this study showed that drying increased significantly the MFA, possibly as a result of lateral deformation of cellulose microfibrils during water desorption from wood cell walls. Moreover, MFA increased when target MC decreased.

The mechanism of surface growth in parenchyma of Avena coleoptiles

1955 ◽  
Vol 3 (2) ◽  
pp. 137 ◽  
Author(s):  
AB Wardrop
Keyword(s):  
Cell Wall ◽  
Tip Growth ◽  
Cell Types ◽  
Cellulose Microfibrils ◽  
Wall Material ◽  
Cell Wall Material ◽  
Cell Enlargement ◽  
Electron Microscopic ◽  
Stages Of Growth ◽  
Preferred Direction

A study has been made of the organization of the cell wall in the parenchyma of Avena coleoptiles at successive stages of growth, using light and electron microscopic methods. It has been observed that extension of the parenchyma involves a progressive separation of the primary pit fields accompanied by an increasing dispersion of the cellulose microfibrils about their preferred direction of orientation. On the basis of this, and ancillary evidence from other cell types, it is suggested that extension growth involves stretching of the cell with the intercalation of new microfibrils into the expanding cell wall framework from the regions of the primary pit fields and penetration of the cell wall by plasmodesmata. It is considered that the evidence is consistent equally with the view either that the cell wall is stretched as water absorption accompanying enlargement takes place, or that cell enlargement is controlled by the synthesis of cell wall material at synthetic centres (pit fields and plasmodesmata) distributed over the cell surface. The concept of bipolar tip growth for coleoptile parenchyma is rejected.

Synchrotron X-ray measurements of cellulose in wood cell wall layers of Pinus densiflora in the transmission and reflectance modes. Part 2: results with axial loading

Holzforschung ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Chang-Goo Lee ◽  
Mariko Yamasaki ◽  
Erina Kojima ◽  
Takanori Sugimoto ◽  
Yasutoshi Sasaki
Keyword(s):  
Cell Wall ◽  
Mechanical Behavior ◽  
Lattice Spacing ◽  
Pinus Densiflora ◽  
Microfibril Angle ◽  
Compressive Load ◽  
Axial Loading ◽  
Cellulose Microfibrils ◽  
Compressive Loads ◽  
Almost All

AbstractThis study applied synchrotron radiation XRD to analyze the mechanical behavior of cellulose microfibrils in wood containing annual rings (thickness: 5 mm), for different layers of the secondary cell wall, under uniaxial load. Cellulose in S2 and in S1 and S3 layers were analyzed respectively, and the data were used to investigate for deformation behavior in the lattice spacing (d004). As a result, the mechanical behavior of cellulose sometimes differed from the behavior of bulk wood. The rigidity of cellulose in the S2 layer was larger than in S1 and S3 layers under both of tensile and compressive loads. However, once standardized with respect to estimated cellulose amount, this standardized rigidity was comparable across all layers and loading conditions. Variation in microfibril angle (MFA) and lattice spacing (d004) of cellulose barely changed at all under compressive load. Under tensile loads, there were both of positive and negative changes in MFA variation in both S2 layer and S1 and S3 layers, while d004 variation had little changes in almost all cases.

Ion Beam Bio-Engineering and Crop Breeding

2010 ◽  
Vol 108-111 ◽  
pp. 536-542
Author(s):  
Tie Gu Wang ◽  
Xue Bin Li ◽  
Tian You Yang ◽  
Wei Dong Wang
Keyword(s):  
Cell Wall ◽  
Plant Cell ◽  
Plant Cell Wall ◽  
Ion Beam ◽  
Crop Improvement ◽  
Low Energy ◽  
Wall Material ◽  
Crop Breeding ◽  
Exogenous Dna ◽  
Bio Engineering

Ion beam bio-engineering was established by Chinese researcher in 1980s. Over thirty years past, there were delightful progress by low energy ion beam induced mutants and crop improvement. When ion beam implant the organism, charge exchanged between ions and organism surfaces. Meanwhile there were ion sputtering, ion penetration and surface damage of plant cell wall material. Owing to etching action of low energy beam to plant cell wall, ion beam mediated exogenous DNA transformation becomes possible. Representative applications and achievements in crop breeding were described.

A survey of the natural variation in biomechanical and cell wall properties in inflorescence stems reveals new insights into the utility of Arabidopsis as a wood model

2013 ◽  
Vol 40 (7) ◽  
pp. 662 ◽  
Author(s):  
Colleen P. MacMillan ◽  
Philip J. O'Donnell ◽  
Anne-Marie Smit ◽  
Rob Evans ◽  
Zbigniew H. Stachurski ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Cell Wall ◽  
Natural Variation ◽  
Lignin Content ◽  
Secondary Growth ◽  
Microfibril Angle ◽  
Biofuel Production ◽  
Arabinogalactan Protein ◽  
Cellulose Microfibrils ◽  
Inflorescence Stems

The natural trait variation in Arabidopsis thaliana (L.) Heynh. accessions is an important resource for understanding many biological processes but it is underexploited for wood-related properties. Twelve A. thaliana accessions from diverse geographical locations were examined for variation in secondary growth, biomechanical properties, cell wall glycan content, cellulose microfibril angle (MFA) and flowering time. The effect of daylength was also examined. Secondary growth in rosette and inflorescence stems was observed in all accessions. Organised cellulose microfibrils in inflorescence stems were found in plants grown under long and short days. A substantial range of phenotypic variation was found in biochemical and wood-related biophysical characteristics, particularly for tensile strength, tensile stiffness, MFA and some cell wall components. The four monosaccharides galactose, arabinose, rhamnose and fucose strongly correlated with each other as well as with tensile strength and MFA, consistent with mutations in arabinogalactan protein and fucosyl- and xyloglucan galactosyl-transferase genes that result in decreases in strength. Conversely, these variables showed negative correlations with lignin content. Our data support the notion that large-scale natural variation studies of wood-related biomechanical and biochemical properties of inflorescence stems will be useful for the identification of novel genes important for wood formation and quality, and therefore biomaterial and renewable biofuel production.

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